I agree. I think a lot of the time they're aware of the contradictions. They'll decide "previously it worked like that, but going forward, it works like this". With Classic Sonic being a separate universe now, I don't think the intention was to solve existing continuity problems (Chaotix, Super Emeralds, two Death Egg 2s), but it inadvertently does. Similarly, the decision that Sonic and humans live in two different worlds that sometimes cross over raises a lot of questions about the Sonic Adventure games, but has the side effect of solving the big contradiction between Sonic Advance 3 and Sonic Unleashed. Which games' art styles don't you think were done with intent? With Sonic Mania, it's obvious what they were going for, and they achieved it. Shadow the Hedgehog looked the way it did by design. Sonic Riders' futuristic extreme sports world was also by design. Sonic 2006's "Sonic in the real world" approach was by design. There's a clear intent behind all of those games, just like Zelda.